10
C6.2.44/0219/E
Figure 9: Control valve pipe connection
Emerson has developed digital solenoid tubing kits for compressors with brazing stub tubes or
with Rotalock connections and 24V or 230V coil
– see
Figures 10 & 11
. The kits are optimized to
fit with or without sound shell and are valid for all compressor sizes using an external visible
solenoid valve.
For digital solenoid valve and complete tubing kits references, see Emerson spare parts software
available at
Figure 10: Piping kit for Rotalock connections
Figure 11: Piping kit for stub tubes
3.3 Discharge check valve
There is no discharge check valve at the discharge port of ZRD*KRE digital compressors since
the high-side pressure is needed to support the operation of the unloader mechanism.
To avoid by-passing during the unloading process back to suction, a dynamic discharge valve is
fitted internally on the discharge port of the fixed scroll. This discharge valve cannot be used with
recycling pump-down because it is not leak-proof during the off period.
3.4 Brazing procedure
IMPORTANT
Blockage! Compressor breakdown!
Maintain a flow of oxygen-free nitrogen
through the system at very low pressure during brazing. Nitrogen displaces
the air and prevents the formation of copper oxides in the system. If allowed
to form, the copper oxide material can later be swept through the system and
block screens such as those protecting capillary tubes, thermal expansion
valves, and accumulator oil return holes.
Contamination or moisture!
Bearing failure!
Do not remove the plugs until
the compressor is set into the unit. This minimises any entry of contaminants
and moisture.
